Social networks have quickly become the most popular places where people communicate and share information, and thus have a significant impact on everyday life. Everything that users share on social networks with other users and their online behavior is, just as behavior in real life, related to their personality traits (Amichai-Hamburger, Fine and Goldstein, 2004). Given the widespread expansion of social networks among generations, it is no wonder that the area has attracted many researchers and psychologists alike. Psychologists who are interested in this area were mainly focused on examining the relationship between the use of social networks and personality traits from the fivefactor personality model examined the relationship between social networks and personality traits from a five-factor personality model. The results of previous studies suggest that there is a relationship between the personality traits and the different aspects of using social networks, as well as the gender and age differences in their usage. Since the previous research has demonstrated inconsistent findings regarding the relationship between different aspects of social networks and personality traits, the aim of this study was to examine the relationship between personality dimensions and social networks addiction. In addition, gender differences in social networks addiction were tested. The sample used in this study consisted of 254 students from the Republic of Croatia. The following measuring instruments were used: The international personality item pool (IPIP), Internet Addiction Scale, and socio-demographic data. There was a relationship between some personality traits of the Five-factor model and social networks addiction. Emotional stability and conscientiousness are negatively related to social networks addiction. There was no correlation between extraversion, openness to experience and comfort and social networks addiction. Also, there was no difference between men and women in social networks addiction.